(1) Field of the Invention
The cephalosporins of the present invention in general possess the usual attributes of such compounds and are particularly useful in the treatment of bacterial infections.
(2) Description of the Prior Art
The cephalosporins are a well-known group of semisynthetic antibacterial agents made originally, for example, by acylation of the 7-amino group of the nucelus 7-aminocephalosporanic acid (7-ACA) and later by similar acylation of nuclei derived therefrom, as by modification of its substituent at the 3-position. Various reviews have appeared in the scientific literature (e.g. Cephalosporins and Penicillins--Chemistry and Biology, edited by Edwin H. Flynn, Academic Press, New York, 1972, and particularly pages 554-569) and in the patent literature, e.g. as in U.S. Pat. Nos. 3,687,948; 3,741,965; 3,743,644; 3,759,904; 3,759,905; 3,766,175; 3,766,906; 3,769,281; 3,796,801; 3,799,923; 3,812,116; 3,813,388; 3,814,754 and 3,814,755 (all U.S. Class 260-243C).
Issued disclosures of 3-thiolated cephalosporins in which the 7-substituent is 7-mandelamido (7-.alpha.-hydroxyphenylacetamido) are found, for example, in U.S. Pat. No. 3,641,021, France No. 73.10112, U.S. Pat. No. 3,796,801, Great Britain No. 1,328,340 (Farmdoc 38983T), U.S. Pat. No. 3,701,775, Japan No. 4844293 (Farmdoc 55334U) and in Hoover et al., J. Med. Chem. 17(1), 34-41 (1974) and Wick et al., Antimicrobial Ag. Chemo., 1(3), 221-234 (1972).
U.S. Pat. No. 3,819,623 (and, for example, also U.K. No. 1,295,841 and West Germany No. 1,953,861) discloses specifically and with working details the preparation of 2-mercapto-1,3,4-thiadiazole-5-acetic acid and its conversion to 7-(1H-tetrazol-1-ylacetamido)-3-(5-carboxymethyl-1,3,4-thiadiazol-2-ylthio methyl)-3-cephem-4-carboxylic acid which is also disclosed in West Germany Offenlegungsschrift No. 2,262,262.